In recent years in order to prevent leakage of business information, there are increasing demands with regard to login commands to personal computers and to controlling entering or exiling rooms. However, since impersonation (or spoofing) is relatively easy with regard to methods of inputting passwords and inserting cards, there is increasing usage of control methods using features of biological objects with which impersonation is difficult.
For example, as an authentication device to authenticate individuals by placing a finger on the device, systems are known in which a surface skin pattern such as a fingerprint or a vein pattern are collated.
Patent Literature 1 discloses a non-contact personal identification device that uses a fingerprint as a biometric feature.
Patent Literature 2 discloses a non-contact personal identification device that uses a finger blood vessel as a biometric feature.
Patent Literature 3 and 4 disclose an authentication imaging device that obtains a fingerprint image and blood vessel image to realize high authentication accuracy.
Patent Literature 5 discloses technology in which, in a biometric authentication device that simultaneously takes fingerprint and vein images, a sensor for detecting placement of the tip region and the base of a finger is provided, and when the tip region and the base of the finger are not in a normal placement, notification of an abnormality in the finger placement is given to a user by flashing a lamp.
Patent Literature 6 discloses technology in which, in order to prevent reduced reproducibility when authentication is performed, due to blood flow being halted when a finger is presented on a guide part and the finger is in pressurized contact with the guide part so that there is a partial lack of a blood vessel pattern, the region used in authentication does not make contact with the device while the finger position is held.
Patent Literature 7 discloses a biometric authentication device in which a detection sensor is provided that makes contact with a prescribed part of a person, and outputs a signal in accordance with the level of pressure by the prescribed part (level of pressing force applied, extent of color change of finger due to pressure, or the like), and a determination is made as to whether or not the state of the prescribed part is one in which hand print information and vein information should be obtained, in accordance with a signal from the detection sensor.
[PTL 1]
Japanese Patent Kokai Publication No. JP2003-085538A
[PTL 2]
Japanese Patent Kokai Publication No. JP-H07-021373A
[PTL 3]
Japanese Patent Kokai Publication No. JP2009-175810A
[PTL 4]
Japanese Patent Kokai Publication No. JP 2009-252052A
[PTL 5]
International Publication No. WO2012/063761
[PTL 6]
Japanese Patent Kokai Publication No. JP2012-098974A
[PTL 7]
Japanese Patent Kokai Publication No. JP2014-102845A